On Tue, Aug 01, 2017 at 09:50:02AM +0100, Dr. David Alan Gilbert wrote: > * Peter Xu (pet...@redhat.com) wrote: > > On Mon, Jul 31, 2017 at 07:52:24PM +0100, Dr. David Alan Gilbert wrote: > > > * Peter Xu (pet...@redhat.com) wrote: > > > > This provides a way to start postcopy ASAP when migration starts. To do > > > > this, we need both: > > > > > > > > -global migration.x-postcopy-ram=on \ > > > > -global migration.x-postcopy-fast=on > > > > > > Can you explain why this is necessary? Both sides already know > > > they're doing a postcopy recovery don't they? > > > > What I wanted to do here is to provide a way to start postcopy at the > > very beginning (actually it'll possibly start postcopy at the first > > loop in migration_thread), instead of start postcopy until we trigger > > it using "migrate_start_postcopy" command. > > > > I used it for easier debugging (so I don't need to type > > "migrate_start_postcopy" every time when I trigger postcopy > > migration), meanwhile I think it can also be used when someone really > > want to start postcopy from the very beginning. > > > > Would such a new parameter makes sense? > > Other than debugging, I don't think there's a real use for it; the > slight delay between starting migration and triggering postcopy has > very little cost.
Then let me drop this patch in next version. I do think I should avoid introducing too many things "for debugging only"... -- Peter Xu
